Mercury is ubiquitous in the environment, and in our mouths in the form of "silver" amalgams. Once introduced to the body through food or vapor, mercury is rapidly absorbed and accumulates in several tissues, leading to increased oxidative damage, mitochondrial dysfunction, and cell death. Mercury primarily affects neurological tissue, resulting in numerous neurological symptoms, and also affects the kidneys and the immune system. It causes increased production of free radicals and decreases the availability of antioxidants. It also has devastating effects on the glutathione content of the body, giving rise to the possibility of increased retention of other environmental toxins

Silver iodide, by contrast, took effect much sooner, when it was as warm at twenty-five to twenty-eight degrees, only a few points below freezing. At fourteen degrees, where other par ticles were just starting to work, silver iodide was in full operation.

Many ways of vaporizing silver iodide were tried. One ex- perimenter, lrving P. Krick of the California Institute of Tech nology, developed a generator consisting of a small firebrick oven inside a steel box about the size of a television set, which has proved to be the most effective. In this one the silver iodide was impregnated in coke and burned at the white heat of 2,500 degrees. Impelled by a fan blowing through the fire, the vapor ized silver iodide rose invisibly from the little furnace and drifted off toward the clouds on the rising air currents, feeding the clouds at the rate of billions of particles a second.

As the silver iodide rose, it also dispersed widely. This was another advantage over dry ice. By the time it arrived at seeding levels, perhaps fifty miles from where it started, then particles could be spread throughout thousands of cubic mile of the atmosphere.